Which matrix multiplication is defined ?

A. CB

Step-by-step explanation:

3 x 2 (C is a 3 by 2) matrix can be multiplied to a 2 x 2 (B is a 2 by 2) matrix since C has 2 columns that are equal to the number of rows in the second matrix B.

A way of checking if two matrices can be multiplied is to first check the number of columns the first matrix contains and then check the number of rows that the second matrix contains.

If the number of columns in the first matrix equal the number of rows in the second matrix then that means it is possible to multiply these matrices.